Calcium Urolithiasis Flashcards
What is the most common type of kidney stone?
Calcium stones
Calcium stones can be calcium oxalate or calcium phosphate.
What are the typical serum and urinary calcium levels in young adults with idiopathic kidney stones?
Normocalcemia and hypercalciuria
This means normal serum calcium but elevated urinary calcium.
What is a common clinical scenario for urolithiasis in young adults?
Healthy male in his 20s with sharp pain in the flank or groin + RBCs in urine
This presentation is typical for kidney stones.
Which gastrointestinal condition increases the risk for calcium oxalate stones?
Crohn disease
Disorders causing fat malabsorption increase this risk.
What is the relationship between fat malabsorption and calcium oxalate stone formation?
More fat retained in GI tract leads to more chelation with calcium, resulting in less calcium available to bind oxalate, which leads to increased oxalate absorption by GI tract and increased urinary oxalate
This increases urinary oxalate absorption.
What are two high-yield etiologies for hypercalcemia related to kidney stones?
- Primary hyperparathyroidism
- Malignancy causing hypercalcemia
Both conditions can lead to the formation of calcium stones.
What is the milk-alkali syndrome?
Increased Calcium + increased bicarbonate + calcium stones
It commonly occurs in patients taking excessive antacids.
Which substances can cause oxalate stones?
- Ethylene glycol (Anti-Freeze)
- Hypervitaminosis C
Both substances are known to lead to oxalate stone formation.
What is the first step in the prevention and treatment of kidney stones?
Adequate hydration
Staying well-hydrated helps to prevent stone formation.
Beyond adequate hydration, what can help in preventing recurrent calcium kidney stones?
Thiazides by decreasing urinary calcium (because they increase reabsorption of calcium)
This mechanism is often tested in exams.
What is the theoretical benefit of alkalinizing the urine? How about acidifying this urine?
Alkalinizing the urine can help treat oxalate stones.
Acidification of the urine can help treat phosphate stones.
